eglfs: Ensure correct z-order of windows

- The main window needs to be at the back always, since it's fullscreen. If the root
window gets in front then there's no way to retrieve the secondary windows.

- Qt::Tool and transient child windows go to front as in other QPAs

Change-Id: I4a2793628250756bc07daaee0763ea7174a7bebd
Pick-to: 6.3 6.4
Reviewed-by: Laszlo Agocs <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/opengl/qopenglcompositor_p.h b/src/opengl/qopenglcompositor_p.h
index 6ab738c58e9..abe8d4959ef 100644
--- a/src/opengl/qopenglcompositor_p.h
+++ b/src/opengl/qopenglcompositor_p.h
@@ -74,6 +74,7 @@ private:
 
     void renderAll(QOpenGLFramebufferObject *fbo);
     void render(QOpenGLCompositorWindow *window);
+    void ensureCorrectZOrder();
 
     QOpenGLContext *m_context;
     QWindow *m_targetWindow;